I used to used mallery dual points with weights instead of vacuum advance then I started using MSD's. If I didn't have to run Vac on the dist, I would not. Run Mech.
I didn't think the 72's had emmission stuff on it? A good guy to ask is Pat McCarthy
or Dave Severson. If it didn't come with it don't put it on there or they might lock that car in at that standerd. Man I used to build cars all the time in Vegas that had to pass emmissions. I put carbs, cams, headers all kinds of stuff then just turned it back when I went to have it checked at the emmissions station. Never had a problem with a new motor not passing. Kurt